Lecture 14: Plant Cell Wall Structures & Function Flashcards
Can the plant cell wall be used as a carbon neutral energy source?
- Breaking down the cell walls for ethanol
Many plant cells have _____ cell walls.
- Two
The ____ can be described as the glue between two plant cells.
- Pectin (in the Middle Lamella)
The main component of cell walls is ______, a _____ polymer. It’s a very abundant organic macromolecule on Earth.
- Cellulose
Cellulose has a long ____-like structure.
- Ribbon
FUN FACT ABOUT CELLULOSE
- It’s stronger than steel of the same diameter
The primary cell wall is produced by _____ cells and is relatively _____ and flexible. It is only made up of 20 - 35% _____.
- Young
- Thin
- Cellulose
In the noncrystalline matrix, _____ forms the rigid structure whereas ______ binds water and has gel-like properties.
- Hemicellulose
- Pectin
Primary cell wall proteins include _____ which are associated with it’s ability to extend and expand when it’s in it’s relaxed state. In it’s cross-linked state, _____ is decreased, and ______ is increased.
- Extensins
- Extendability
- Strength
Cellulose microfibrils are made in the ____ ____.
- Plasma membrane
Pectin and hemicellulose are made in the ____ _____ and transported to the wall in _____.
- Golgi apparatus
- Vesicles
Cell Wall Extensins are made in the _____ _____.
- Rough ER
Cell walls (3) functions:
- Structural support and influences cell morphology
- Protection (can’t be digested by many organisms)
- Prevents excessive water uptake
Cellulose-producing rosettes move ______ to the cortical microtubules.
- Parallel
Orientation of the cellulose microfibrils influences cell morphology. If they’re randomly orientated the cell will ……
- Expand equally in all directions
If orientation of cell microfibrils are at right angles the cell will ……
- Expand longitudinally
Cell walls can also act as an active protection barrier. Give examples.
- A plant being attacked buy a fungi, neighbouring cells secrete a fungicide.
Turgor pressure limits the amount of _____ uptake and contributes to structural support.
- Water
Not all plants have a secondary cell wall. They are produced only after cell growth has _____.
- Stopped
Describe the secondary cell wall structure. Is there more cellulose or more pectin?
- Made up of multiple layers
- Microfibrils in each layer have different orientations (this strengthens the secondary wall)
- More cellulose
Where is Lignin found and what is it’s structure?
- Cell Wall (second most abundant organic macromolecule)
- Complex Polymer
What is the function of Lignin?
- Strength, rigidity, hydrophobicity
The plasmodesmata allows the free exchange of ______ molecules.
- Small
How do viruses move through the plasmodesmata?
- By gating (movement) proteins
